A welding cane of the type having a laser beam conducted by an optical fiber to a welding head of the cane is known in the art, the welding head comprising an optical device for focusing the laser beam and a mirror 9A reflecting the laser beam towards a welding site external to the welding head.
Welding canes are utilized in particular for sealing sleeve welding operations in the pressurized primary coolant pipes of a pressurized water nuclear reactor steam generator.
A consequence of the high power of the laser beam utilized in this type of welding cane is that, in the event of a defect appearing in the optical fiber, the latter rapidly deteriorates and may be destroyed at a rate of several tens of centimeters per second.